Lucas Yahontov is one of five children of Kiyoshi, James, and Alexei Yahontov (though he's the only one of all of them with a Simpedia page of his own). He was married once and had one daughter by his wife before they divorced. His ex-wife, daughter, and son-in-law died in a tragic rock climbing accident in Mt. Komorebi and he's raised his twin grandsons alone since then. He never remarried. He went to the Foxbury Institute and majored in psychology, and he was also a member of the Chi Beta Gamma fraternity while there, and has been a very generous donor to the university throughout his career.
He had no formal training as an actor, according to a vlog post, and learned it "on the go". He started acting as an extra in Growing Up Crumplebottom before being promoted to regular then main cast as audience response to his character was really positive. That launched him into the spotlight and he became a global superstar while he was still a young adult, starring in blockbusters like Of Tea & Treachery and Captain Sigma: Olympus Landing. He's been less active as an actor recently, though, and has instead been focusing on his (very prolific) vlog, his personal brand of wellness products and cosmetics, and modelling.
Unlike many other celebrities of his level of fame, he doesn't seem particularly shy of the media and paparazzi, and has hosted multiple parties and meet & greets. He also seems to love giving people autographs and taking pictures with his fans, so his entire life trajectory has been extensively documented.
Perhaps of interest to Peter is the fact that he is incredibly fit, even as an elder, and he often doesn't wear any clothes at home and does not particularly seem to avoid being photographed then either.